Stabilizing ceftolozane

ABSTRACT

Pharmaceutical compositions can include an amount of a ceftolozane and a stabilizing agent in a formulation for parenteral administration.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 61/792,092, filed Mar. 15, 2013; U.S. Provisional Application No. 61/793,007, filed Mar. 15, 2013; U.S. Provisional Application No. 61/882,936, filed Sep. 26, 2013; and U.S. Provisional Application No. 61/893,436, filed Oct. 21, 2013. The contents of these applications are incorporated hereby by reference in their entireties.

TECHNICAL FIELD

This disclosure relates to pharmaceutical compositions comprising ceftolozane.

BACKGROUND

Ceftolozane is a cephalosporin antibacterial agent, also referred to as CXA-101, FR264205, or by chemical names such as (6R,7R)-3-[(5-amino-4-{[(2-aminoethyl)carbamoyl]amino}-1-methyl-1H-pyrazol-2-ium-2-yl)methyl]-7-({(2Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-[(1-carboxy-1-methylethoxy)imino]acetyl}amino)-8-oxo-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylate, and 7β-[(Z)-2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methylethoxyimino)acetamido]-3-{3-amino-4-[3-(2-aminoethyl)ureido]-2-methyl-1-pyrazolio}methyl-3-cephem-4-carboxylate.

The prior art describes a variety of ceftolozane salts. For example, U.S. Pat. No. 7,129,232 discloses ceftolozane hydrogen sulfate salt among other salts “with a base or an acid addition salt such as a salt with an inorganic base, for example, an alkali metal salt [e.g., sodium salt, potassium salt, etc.], an alkaline earth metal salt [e.g., calcium salt, magnesium salt, etc.], an ammonium salt; a salt with an organic base, for example, an organic amine salt [e.g., trimethylamine salt, triethylamine salt, pyridine salt, picoline salt, ethanolamine salt, triethanolamine salt, dicyclohexylamine salt, N,N′-dibenzylethylenediamine salt, etc.]; an inorganic acid addition salt [e.g., hydrochloride, hydrobromide, sulfate, hydrogen sulfate, phosphate, etc.]; an organic carboxylic or sulfonic acid addition salt [e.g., formate, acetate, trifluoroacetate, maleate, tartrate, citrate, fumarate, methanesulfonate, benzenesulfonate, toluenesulfonate, etc.]; and a salt with a basic or acidic amino acid [e.g., arginine, aspartic acid, glutamic acid, etc.].” Ceftolozane sulfate is a pharmaceutically acceptable ceftolozane salt of formula (I) that can be formulated for intravenous administration or infusion.

Certain pharmaceutical compositions containing ceftolozane are useful as antibiotics for the treatment of certain serious infections, including serious complicated intra-abdominal infections and complicated urinary tract infections. The ceftolozane pharmaceutical compositions can be administered as intravenous antibacterial agents to treat these infections. The antibacterial activity of ceftolozane is believed to result from its interaction with penicillin binding proteins (PBPs) to inhibit the biosynthesis of the bacterial cell wall which acts to stop bacterial replication. Ceftolozane sulfate is a pharmaceutically acceptable ceftolozane salt of formula (I) that can be formulated for intravenous administration or infusion. Antibacterial pharmaceutical compositions can include a therapeutically effective unit dose of a pharmaceutically acceptable salt of ceftolozane formulated for intravenous administration.

Ceftolozane is unstable in certain lyophilized pharmaceutical compositions initially evaluated for intravenous administration. In particular, a decrease in ceftolozane purity was observed by high purity liquid chromatography (HPLC) after stability testing. In one stability test, the residual rate (i.e., the amount of ceftolozane remaining in a sample as detected by HPLC) of ceftolozane after 3 days at 70 degrees C. was about 50% in the absence of a stabilizing agent (e.g., “control” data shown in FIG. 3, a portion of Table 2 and a comparative portion of Example 1). In another stability test, the amount of ceftolozane detected by HPLC in a sample decreased by over 5% over 7 days at 60 degrees C. (e.g., “none” column of Table 3, a comparative portion of Example 1). This stability testing pointed to the need to develop novel ceftolozane formulations providing increased ceftolozane stability. U.S. Pat. No. 7,129,232 discloses that “auxiliary substances” such as “stabilizing agents . . . and other commonly used additives” may be included in pharmaceutical compositions comprising ceftolozane or many other cephalosporin compounds “if needed.” However, the disclosure does not disclose a reduction in ceftolozane purity in pharmaceutical compositions containing ceftolozane sulfate, or the formation of additional related substances observed during stability testing. Nor does the disclosure provide guidance on the formation of ceftolozane pharmaceutical compositions to increase ceftolozane purity during stability testing or control the relative amounts of ceftolozane related substances detected by HPLC peak formation during stability testing.

In view of the above, there is a need for pharmaceutical preparations containing ceftolozane compounds having improved ceftolozane stability.

SUMMARY

Ceftolozane can be stabilized in pharmaceutical compositions comprising ceftolozane and a stabilizing-effective amount of a stabilizing agent selected from the group consisting of: sodium chloride, dextran 40, lactose, maltose, tehalose and sucrose. The invention is based in part on the surprising discovery that ceftolozane pharmaceutical compositions comprising these stabilizing agents demonstrate improved ceftolozane residual rates in solid compositions (e.g., % ceftolozane in a solid form remaining after 3 days at 70 degrees C. as measured by HPLC) and/or chemical stability (e.g., lower reduction in ceftolozane purity measured by HPLC after 7 days at 60 degrees C. in a stability test) compared control samples comprising ceftolozane without a stabilizing agent.

Accordingly, preferred pharmaceutical antibiotic compositions can include ceftolozane sulfate and a stabilizing agent (e.g., 300 to 500 mg of a stabilizing agent per 1,000 mg ceftolozane active) in a lyophilized unit dosage form (e.g., powder in a vial). The unit dosage form can be dissolved with a pharmaceutically acceptable carrier (e.g., 0.9% sodium chloride aqueous isotonic saline and/or water for injection), and then intravenously administered. In certain ceftolozane compositions, the stabilizing agent can be selected from the group consisting of: sodium chloride, lactose, maltose and dextran 40, and/or selected from the group consisting of: sodium chloride, trehalose and sucrose.

The initial amount of the stabilized ceftolozane in the pharmaceutical composition is an amount providing a weight ratio of 1,000 mg to a stabilizing-effective amount (e.g., about 100-500 mg and preferably about 300 mg-500 mg) of one or more stabilizing agent(s). The stabilizing amount is preferably included in an amount of about 300-500 mg per 1 g of ceftolozane active. The stabilized ceftolozane is preferably a pharmaceutically acceptable salt, such as ceftolozane sulfate.

The increased stability of stabilized ceftolozane combined with a stabilizing effective amount of a stabilizing agent in the pharmaceutical compositions can be measured by high performance liquid chromatography (HPLC). Unless otherwise indicated, HPLC measurements can be observed by HPLC using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C. (Example 5). In one aspect, the stabilized ceftolozane pharmaceutical compositions after 3 days at 70 degrees C. comprises at least about 70% of an initial amount of the stabilized ceftolozane in the pharmaceutical composition (i.e., a residual rate of about 70% or greater, as shown in Example 1), where the % of ceftolozane is measured by high performance liquid chromatography (HPLC) according to Example 5. A stabilized ceftolozane pharmaceutical composition comprising ceftolozane and a stabilizing agent selected from the group consisting of: sodium chloride, dextran 40, lactose, and maltose can retain at least about 70% of an initial amount of the stabilized ceftolozane in the pharmaceutical composition after 3 days at 70 degrees C. (i.e., a residual rate of about 70% or greater, as shown in Example 1), where the % of ceftolozane is measured by HPLC according to Example 5. In another aspect, the stabilized ceftolozane pharmaceutical compositions are characterized by a reduction in ceftolozane of less than about 5% after 7 days at 60 degrees C., where the % reduction of ceftolozane is measured by HPLC according to Example 5. The stabilized ceftolozane pharmaceutical composition comprising ceftolozane and a stabilizing agent selected from the group consisting of: sodium chloride, trehalose and sucrose can lose less than 5% of the amount of ceftolozane after 7 days at 60 degrees C., where the % loss of ceftolozane is measured by HPLC according to Example 5.

Stabilized ceftolozane can be obtained by a process comprising lyophilizing a solution (e.g., an aqueous solution) including ceftolozane and a stabilizing agent to obtain a lyophilized stabilized ceftolozane pharmaceutical composition. The solution can include 1,000 mg of ceftolozane active and about 300-500 mg of one or more stabilizing agents, in addition to other components such as citric acid and/or L-arginine.

In an embodiment, provided herein is container containing a unit dosage form of a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections, the pharmaceutical composition can include 1,000 mg of ceftolozane active, L-arginine, citric acid and about 300-500 mg of a stabilizing agent selected from the group consisting of: sodium chloride, trehalose, and sucrose, wherein the pharmaceutical composition after 3 days at 70 degrees C. comprises at least about 70% of an initial amount of the ceftolozane active in the pharmaceutical composition. The vial can contain 300 mg of a stabilizing agent (e.g., selected from the group consisting of trehalose and sucrose, or other stabilizing agents). The pharmaceutical composition in the vial can be obtained by lyophilizing an aqueous solution comprising about 300-500 mg of the stabilizing agent, an amount of ceftolozane sulfate containing 1,000 mg of ceftolozane active, citric acid, and L-arginine to obtain the pharmaceutical composition as a lyophilized composition. Optionally, the vial can further include tazobactam (e.g., tazobactam sodium).

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are chromatograms of CXA-101 ceftolozane drug substance obtained from a lyophilization process. The chromatograms were obtained according to the analytical method described in Example 5.

FIG. 2 is a table (Table 1) of HPLC peak values in units of retention times relative to the retention time of ceftolozane (“RRT” or relative retention time), according to the HPLC method of Example 5.

FIG. 3 is a table (Table 2) of data from the screening of different stabilizing agents.

FIG. 4 is a diagram of a lyophilization process referenced in Example 4.

DETAILED DESCRIPTION

Ceftolozane can be stabilized in pharmaceutical composition comprising ceftolozane and a stabilizing effective amount of a stabilizing agent selected from the group consisting of: sodium chloride, dextran 40, lactose, maltose, tehalose and sucrose. The stabilizing agent and the stabilizing effective amount of the stabilizing agent for combination with ceftolozane were determined by high performance liquid chromatography (HPLC) analysis, for example by detecting the ratio of peak areas obtained for ceftolozane compared to peaks for other substances.

Preferred stabilized ceftolozane compositions have a ceftolozane residual rate of greater than the residual rate measured for a comparable ceftolozane composition without the stabilizing agent. Unless otherwise indicated, the residual rate is measured by detecting the amount of ceftolozane in a sample before and after a stability test using HPLC, and determining the percentage of ceftolozane last during the stability test.

Referring to Example 1 (including Table 2, FIG. 3), the residual rate of ceftolozane in the control sample without a stabilizing agent (i.e., 100 mg of ceftolozane) after 3 days at 70 degrees C. was 51.2%, meaning that the HPLC peak area after the stability test for ceftolozane was about 51.2% of the HPLC peak area for ceftolozane at the start of the stability test (i.e., 3 days at 70 degrees C.). Sodium chloride, dextran 40, lactose and maltose all showed higher ceftolozane residual rates than the control in Example 1, while ceftolozane was less stable than the control when combined with fructose, xylitol, sorbitol and glucose (e.g., as evidenced by a residual rate lower than that of the control). In one embodiment, stabilized ceftolozane compositions comprise ceftolozane (e.g., ceftolozane sulfate) and a stabilizing effective amount of a stabilizing agent selected from the group consisting of: sodium chloride, dextran 40, lactose and maltose, where the stabilizing effective amount provides a residual rate of at least 51.2% for the ceftolozane in the stabilized ceftolozane composition after 3 days at 70 degrees C. Preferably, the stabilized ceftolozane pharmaceutical compositions after 3 days at 70 degrees C. can comprise at least about 70% of an initial amount of the stabilized ceftolozane in the pharmaceutical composition (i.e., a residual rate of about 70% or greater, as shown in Example 2), where the % of ceftolozane is measured by high performance liquid chromatography (HPLC) according to Example 5.

Referring to Example 1 (Table 3), stabilized ceftolozane compositions are characterized by a reduction in ceftolozane of less than about 5% after 7 days at 60 degrees C., where the % reduction of ceftolozane is measured by HPLC according to Example 5. The stabilized ceftolozane pharmaceutical composition comprising ceftolozane and a stabilizing agent selected from the group consisting of: sodium chloride, trehalose and sucrose can lose less than 5% of the amount of ceftolozane after 7 days at 60 degrees C., where the % loss of ceftolozane is measured by HPLC according to Example 5. Sodium chloride, trehalose and sucrose all showed reduced reductions in ceftolozane purity after a 7 day stability test at 60 degrees C. (as measured by the % HPLC peak corresponding to ceftolozane before and after the stability test). In one embodiment, stabilized ceftolozane compositions comprise ceftolozane (e.g., ceftolozane sulfate) and a stabilizing effective amount of a stabilizing agent selected from the group consisting of: sodium chloride, trehalose and sucrose, where the stabilizing effective amount provides a reduction in ceftolozane purity of not more than about 5% (e.g, not more than about 4%) for the ceftolozane in the stabilized ceftolozane composition after 3 days at 70 degrees C.

Various ceftolozane compositions are described herein. One stabilized ceftolozane composition comprises ceftolozane (e.g., ceftolozane sulfate), L-arginine, citric acid, and a stabilizing agent. Preferably, the stabilized ceftolozane composition comprises 1,000 mg of ceftolozane active, L-arginine and stabilizing-effective amount of the stabilizing agent. The stabilizing effective amount can be readily determined using HPLC and a stability test as disclosed herein. The stabilizing-effective amount can be effective to provide: (1) a residual rate measured by HPLC of ceftolozane of at least about 51.2% (including, e.g., at least about 70%, and at least about 80%) after 3 days at 70 degrees C. and/or (2) a reduction in ceftolozane purity measured by HPLC of not more than about 5.11% (including, e.g., reductions of not more than about 5%, or 4%) after 7 days at 60 degrees C. Examples of stabilizing effective amounts include 100 mg-500 mg of the stabilizing agent per 1,000 mg of the ceftolozane active, more preferably about 300-500 mg of the stabilizing agent per 1,000 mg of the ceftolozane active.

Accordingly, provided herein is a pharmaceutical composition comprising stabilized ceftolozane and a stabilizing agent selected from the group consisting of: sodium chloride, dextran 40, lactose, maltose, tehalose and sucrose, wherein the pharmaceutical composition after 3 days at 70 degrees C. comprises at least about 70% of an initial amount of the stabilized ceftolozane in the pharmaceutical composition.

Pharmaceutical compositions comprising ceftolozane and stabilizing-effective amount of a stabilizing agent can be obtained by lyophilization. As is known to those skilled in the art, lyophilization is a process of freeze-drying in which water is sublimed from a frozen solution of one or more solutes. Specific methods of lyophilization are described in Remington's Pharmaceutical Sciences, Chapter 84, page 1565, Eighteenth Edition, A. R. Gennaro, (Mack Publishing Co., Easton, Pa., 1990). A pharmaceutical composition comprising ceftolozane can be prepared by adding a stabilizing amount of sodium chloride in a fixed ratio to ceftolozane in an aqueous solution prior to lyophilization, then lyophilizing the solution to obtain a lyophilized composition comprising sodium chloride and ceftolozane.

Provided herein is a pharmaceutical composition comprising stabilized ceftolozane obtained by a process comprising lyophilizing a composition including ceftolozane and a stabilizing agent selected from the group consisting of: sodium chloride, dextran 40, lactose, maltose, tehalose and sucrose, to obtain a lyophilized stabilized ceftolozane pharmaceutical composition.

In particular, the pharmaceutical antibiotic compositions can include stabilized ceftolozane sulfate obtained by a process comprising the steps of lyophilizing an aqueous solution containing ceftolozane and a stabilizing-effective amount of a stabilizing agent, where the stabilizing-effective amount of the stabilizing agent is about 100 to 500 mg (preferably 300-500 mg) of the stabilizing agent per 1,000 mg ceftolozane active in the aqueous solution prior to lyophilization. A therapeutically effective amount of ceftolozane (e.g., ceftolozane sulfate) and a stabilizing-effective amount of the stabilizing agent can be dissolved in an aqueous solution that can be lyophilized to obtain a stabilized ceftolozane pharmaceutical composition.

The pharmaceutical compositions may comprise other additional components including stabilizers, pH adjusting additives (e.g., buffers) and the like. Non-limiting examples of these additives include citric acid and L-arginine. For example, the pharmaceutical antibiotic compositions can include ceftolozane sulfate obtained by a process comprising the steps of lyophilizing an aqueous solution containing ceftolozane sulfate with a stabilizing amount of one or more stabilizing agents (e.g., a total of about 300 mg to 500 mg of sodium chloride, trehalose and/or sucrose per 1,000 mg ceftolozane active), with L-arginine, and citric acid in the aqueous solution prior to lyophilization. The use of the stabilizing-effective amount of the stabilizing agent results in greater ceftolozane stability, while an amount of L-arginine can be used that is effective to adjust pH and to increase the solubility of ceftolozane, and citric acid can be included in an amount effective to reduce or prevent discoloration of the product, due to its ability to chelate metal ions. The aqueous solution can be subsequently lyophilized to obtain a stabilized lyophilized ceftolozane sulfate composition comprising ceftolozane sulfate, one or more stabilizing agents each in stabilizing-effective amount(s), L-arginine and citric acid.

In other embodiments, pharmaceutical compositions comprising ceftolozane can be obtained by methods that include the steps of: (1) adding a stabilizing-effective amount of a stabilizing agent to ceftolozane followed by co-lyophilizing the ceftolozane and the stabilizing agents; and (2) combining the lyophilized ceftolozane of step (1) with other components (e.g., a β-lactamase inhibitor, such as tazobactam, or a lyophilized β-lactamase inhibitor, such as a lyophilized tazobactam) to obtain the pharmaceutical composition.

Pharmaceutical compositions comprising ceftolozane can be formulated to treat infections by parenteral administration (including subcutaneous, intramuscular, and intravenous) administration. Pharmaceutical compositions may additionally comprise excipients, stabilizers, pH adjusting additives (e.g., buffers) and the like. In one particular embodiment, the pharmaceutical compositions described herein are formulated for administration by intravenous injection or infusion. Pharmaceutical antibiotic compositions can include ceftolozane sulfate and stabilizing amount of a stabilizing agent (e.g., 100 mg to 500 mg of the stabilizing agent(s) per 1,000 mg ceftolozane active) in a lyophilized unit dosage form (e.g., powder in a vial). The unit dosage form can be dissolved with a pharmaceutically acceptable carrier, and then intravenously administered. In another aspect, pharmaceutical antibiotic compositions can include ceftolozane sulfate obtained by a process comprising the steps of lyophilizing an aqueous solution containing ceftolozane and a stabilizing amount of one or more stabilizing agent(s), where the stabilizing-effective amount of the stabilizing agent is about 100 mg to 500 mg (preferably 300 mg to 500 mg) of sodium chloride per 1,000 mg ceftolozane active in the aqueous solution prior to lyophilization.

In one aspect, provided herein is a method for the treatment of bacterial infections in a mammal, comprising administering to said mammal a therapeutically effective amount of a pharmaceutical composition prepared according to the methods described herein. A method for the treatment of bacterial infections in a mammal can comprise administering to said mammal a therapeutically effective amount of a pharmaceutical composition comprising ceftolozane sulfate and sodium chloride. Non-limiting examples of bacterial infections that can be treated by the methods of the invention include infections caused by: aerobic and facultative gram-positive microorganisms (e.g., Staphylococcus aureus, Enterococcus faecalis, Staphylococcus epidermidis, Streptococcus agalactiae, Streptococcus pneumonia, Streptococcus pyogenes, Viridans group streptococci), aerobic and facultative gram-negative microorganisms (e.g., Acinetobacter baumanii, Escherichia coli, Haemophilus influenza, Klebsiella pneumonia, Pseudomonas aeruginosa, Citrobacter koseri, Moraxella catarrhalis, Morganella morganii, Neisseria gonorrhoeae, Proteus mirabilis, Proteus vulgaris, Serratia marcescens, Providencia stuartii, Providencia rettgeri, Salmonella enterica), gram-positive anaerobes (Clostridium perfringens), and gram-negative anaerobes (e.g., Bacteroides fragilis group (e.g., B. fragilis, B. ovatus, B. thetaiotaomicron, and B. vulgates), Bacteroides distasonis, Prevotella melaninogenica). In certain embodiments of the methods described herein, bacterial infection is associated with one or more of the following conditions: complicated intra-abdominal infections, complicated urinary tract infections (cUTIs) and pneumonia (e.g., community-acquired, or nosocomial pneumonia). Community-acquired pneumonia (moderate severity only) can include infections caused by piperacillin-resistant, beta-lactamase producing strains of Haemophilus influenza. Nosocomial pneumonia (moderate to severe) caused by piperacillin-resistant, beta-lactamase producing strains of Staphylococcus aureus and by Acinetobacter baumanii, Haemophilus influenzae, Klebsiella pneumoniae, and Pseudomonas aeruginosa.

The stabilized ceftolozane composition can be provided in a unit dosage form container, such as a vial. The unit dosage form container can contain a unit dose of a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections, the pharmaceutical composition comprising a therapeutically effective amount of ceftolozane sulfate and the stabilizing-effective amount of one or more stabilizing agent(s). Optionally, the unit dosage form container can further include tazobactam (e.g., tazobactam sodium or tazobactam arginine) in a ratio of 1,000 mg ceftolozane active per 500 mg of tazobactam acid. The unit dosage form composition preferably includes a total of 1,000 mg or 2,000 mg of ceftolozane active provided as ceftolozane sulfate. The stabilized ceftolozane composition can be characterized by a residual ceftolozane rate of at least about 50% and preferably at least about 70% after 3 days at 70 degrees C. as identified by high performance liquid chromatography (HPLC) measurements made using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C. The stabilized ceftolozane composition can be characterized by a reduction in ceftolozane purity of not more than about 5% and preferably not more than 4% after 7 days at 60 degrees C. as identified by high performance liquid chromatography (HPLC) measurements made using a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.

Accordingly, provided herein is a unit dosage form container (e.g., a bag, vial, or the like) of a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections, the pharmaceutical composition comprising 1,000 mg of ceftolozane active, L-arginine, citric acid and about 300-500 mg of a stabilizing agent selected from the group consisting of: sodium chloride, trehalose, and sucrose, wherein the pharmaceutical composition after 3 days at 70 degrees C. comprises at least about 70% of an initial amount of the ceftolozane active in the pharmaceutical composition.

Also provided herein is a unit dosage form container (e.g., a bag, vial, or the like) of a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections, the pharmaceutical composition comprising 1,000 mg of ceftolozane active, L-arginine, citric acid and about 300-500 mg of a stabilizing agent selected from the group consisting of: sodium chloride and a non-reducing sugar (e.g., trehalose, and sucrose), wherein the pharmaceutical composition after 3 days at 70 degrees C. comprises at least about 70% of an initial amount of the ceftolozane active in the pharmaceutical composition.

The stabilized ceftolozane pharmaceutical composition in the unit dose form can be obtained by a process comprising the steps of: (a) lyophilizing a first aqueous solution in the absence of tazobactam, the first aqueous solution comprising ceftolozane sulfate, a total of 300 mg to 500 mg of a stabilizing agent (e.g., sodium chloride, trehalose and/or sucrose) per 1,000 mg of ceftolozane active, L-arginine and/or citric acid in an amount effective to adjust the pH of the first aqueous solution to 6-7 prior to lyophilization to obtain a first lyophilized ceftolozane composition. Optionally, the stabilized ceftolozane pharmaceutical composition is obtained by a process further comprising: (b) combining the first lyophilized ceftolozane composition with tazobactam under conditions where the ceftolozane and tazobactam do not react. For example, the first lyophilized ceftolozane composition can be combined with crystalline tazobactam material (e.g., crystalline tazobactam arginine and/or tazobactam sodium). Alternatively or additionally, the stabilized ceftolozane pharmaceutical composition can be obtained by a process further comprising: (b) lyophilizing a second solution in the absence of ceftolozane, the second solution comprising tazobactam acid being lyophilized to form a second lyophilized tazobactam composition; and (c) blending the first lyophilized ceftolozane composition and the second lyophilized tazobactam composition to obtain a blended pharmaceutical composition in the unit dosage form.

As used herein, “treating,” “treat,” or “treatment” describes the management and care of a patient for the purpose of combating a disease, condition, or disorder and includes the administration of a pharmaceutical composition of the present invention to alleviate the symptoms or complications of a disease, condition or disorder, or to reduce the extent of the disease, condition or disorder. The term “treat” can also include treatment of a cell in vitro or an animal model.

By a “therapeutically effective amount” of a compound of the invention is meant a sufficient amount of the compound to treat the disorder (e.g., bacterial infection). The specific therapeutically effective amount that is required for the treatment of any particular patient or organism (e.g., a mammal) will depend upon a variety of factors including the disorder being treated and the severity of the disorder; the activity of the specific compound or composition employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts (see, for example, Goodman and Gilman's, “The Pharmacological Basis of Therapeutics”, Tenth Edition, A. Gilman, J. Hardman and L. Limbird, eds., McGraw-Hill Press, 155-173, 2001, which is incorporated herein by reference in its entirety). The therapeutically effective amount for a given situation can be readily determined by routine experimentation and is within the skill and judgment of the ordinary clinician.

Unless otherwise indicated, as used herein, the term “related substances” with respect to HPLC detection refers to all the ceftolozane related process impurities and degradation products other than ceftolozane separated and detected by HPLC according to Example 5. Unless otherwise indicated, as used herein, the term “% related substances” refers to the % of the total HPLC peak area obtained by Example 5 attributed to all the ceftolozane related process impurities and degradation products other than ceftolozane.

Illustrative Examples of Selected Embodiments of the Invention Example 1 Screening of Stabilizing Agents

In a first stability test, nine stabilizing agents were screened with ceftolozane, including sodium chloride, fructose, xylitol, sorbitol, dextran 40, lactose, glucose, maltose, and D-mannitol. FIG. 3 (Table 2) shows the data obtained from the stability study. The purity of the ceftolozane in a composition comprising 100 mg ceftolozane and 100 mg of one of the stabilizing agents after 3 days at 70° C. was compared to a composition comprising 100 mg ceftolozane but no stabilizing agent. As shown in Table 2, the ceftolozane compositions comprising sodium chloride, dextran 40, lactose, or maltose were demonstrated to be more stable than the other ceftolozane compositions comprising the other stabilizing agents, or no stabilizing agent. Sodium chloride and maltose were selected for further investigation.

In a second stability test, five samples were prepared, the components of which are shown in Table 3 below. The stabilizing effect of other non-reducing sugars such as sucrose and trehalose, as well as polyvinylpyrrolidone (PVP), was also evaluated in a ceftolozane formulation. Each sample contained 1000 mg of ceftolozane active, 40 mg citric acid monohydrate (equivalent of 36 mg citric acid anhydrous), and the same amount of L-arginine. Stabilizing reagents in four samples are 480 mg sodium chloride, 300 mg of trehalose, 300 mg of sucrose, and 300 mg of PVP, respectively. One sample was a control that contained no stabilizing reagent. The samples were in lyophilized form and stored at 60° C. for 7 days. The purities of the samples were monitored by HPLC on day 0, day 1, day 3 and day 7.

TABLE 3 Comparison between stabilizing reagents Excipient NaCl Trehalose Sucrose PVP None Ceftolozane 1000 1000 1000 1000 1000 amount Excipient 480 300 300 300 N/A amount Purity: t₀ 98.42 98.09 98.14 97.89 97.94 60° C./1 d 97.85 96.73 96.97 96.05 96.15 60° C./3 d 97.21 95.36 95.81 94.57 94.53 60° C./7 d 95.65 94.21 94.19 92.78 92.06 Purity Δ (0-7 d) −2.77% −3.88% −3.95% −5.11% −5.88%

As shown in Table 3, the samples containing sodium chloride, and non-reducing sugars (e.g., trehalose and sucrose) showed improved ceftolozane stability in solid compositions (e.g., reduction in ceftolozane purity of less than about 5% as measured by the HPLC method of Example 5). For example, the purity of ceftolozane in the sample containing sodium chloride had less than 3% purity drop over 7 days (as measured by HPLC of Example 5), while samples with stabilizing-effective amounts of trehalose and sucrose had less than 4% reduction in ceftolozane purity during the stability test at 60 degrees C. for 7 days.

This experiment further supports the discovery that the stabilizing agents sodium chloride, and non-reducing sugars (e.g., trehalose and sucrose) provide improved ceftolozane stability compared to Polyvinylpyrrolidone (PVP) and a control (“None” in table 3) without any stabilizing agent.

Example 2 Stability Study of Ceftolozane Compositions Comprising Sodium Chloride, or Maltose, or No Stabilizing Agent

Three ceftolozane compositions were prepared, the components of which are shown in Table 4. These compositions were put in a stressed stability study at 70° C. for 3 days and 6 days. The purity of the ceftolozane in the compositions was analyzed using the HPLC method described in Example 5.

TABLE 4 Ceftolozane Compositions CEF/no stabilizer 9.5 g active Ceftolozane (Control) 5.7 g L-Arginine 200 mg Citric acid CEF/maltose 9.5 g active Ceftolozane 5.7 g L-Arginine 200 mg Citric acid 5 g Maltose H₂O CEF/sodium chloride 9.5 g active Ceftolozane 5.7 g L-Arginine 200 mg Citric acid 4.6 g Sodium Chloride

The results are shown in Table 5 where only the most significant composition peaks (P1, P7, and P12) obtained by HPLC are shown. It was found that the composition comprising maltose (CEF/maltose) contained a significantly large amount of the composition P12 peak, which was identified as having the formula (II):

In addition, the presence of maltose produced a particularly aggregated powder after lyophilization. In contrast, the ceftolozane composition comprising sodium chloride (CEF/sodium chloride) was much more stable than the ceftolozane composition comprising maltose or the ceftolozane composition comprising no stabilizing agent.

TABLE 5 Stability Study of Ceftolozane Compositions Comprising Sodium Chloride, or Maltose, or No Stabilizing Agent Time (days) P1 P7 P12 Total CEF/no stabilizer 0 0.49 0.69 0.00 1.98 3 3.06 1.29 0.00 8.48 6 4.11 1.49 0.00 10.83 CEF/maltose 0 0.41 0.65 0.15 1.91 3 2.85 1.02 3.44 10.08 6 3.45 1.12 4.01 11.65 CEF/sodium chloride 0 0.20 0.62 0.00 1.64 3 1.70 0.85 0.00 4.29 6 2.86 1.05 0.00 6.70

Example 3 Manufacturing Procedure of Bulk (Tray) Lyophilized Ceftolozane

There are four main steps in the manufacture of CXA-101 bulk drug product: dissolution, sterile filtration, bulk lyophilization, and packaging into Sterbags®. These four main steps are composed of a total of 20 minor steps. The CXA-101 bulk drug product manufacturing process is presented below.

I. Dissolution

1. The prescribed amount of water for injection (“WFI”) is charged into the dissolution reactor.

2. A prescribed amount of citric acid is added.

3. The solution is cooled at 5° C. to 10° C.

4. A prescribed amount of CXA-101 drug substance is added to the solution.

5. A prescribed amount of L-arginine is slowly added to the solution.

6. A check for complete dissolution is performed. Solution pH is verified to be in the target range of 6.5 to 7.0.

7. A prescribed amount of sodium chloride is added to the solution.

8. A check for complete dissolution is performed. Solution pH is verified to be in the target range of 6.0 to 7.0. If the pH is out of this range adjust with either L-Arginine or citric acid.

9. WFI is added to bring the net weight to 124.4 kg and the solution is mixed well.

10. Samples are withdrawn for testing of final pH.

II. Sterile Filtration

11. The solution is passed through the filter (pore size 0.45 μm) followed by double filters (pore size 0.22 μm) onto a shelf on the Criofarma lyophilizer.

12. The line is washed with WFI.

13. The washing solution is passed from Step 12 through sterile filtration.

III. Bulk Lyophilization

14. The washing solution is loaded onto a separate shelf in the lyophilizer (and later discarded).

15. The solution is lyophilized until dry.

16. The product shelf is cooled to 20° C.±5° C.

IV. Packaging into Sterbags®

17. The lyophilized bulk drug product powder is milled.

18. The milled powder is sieved.

19. The sieved powder is blended for 30 minutes.

20. The powder is then discharged into Sterbags®

Prefiltration and Sterile-Filtration

Filtrate the compounded solution with a sterile tilter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter (Durapore®, Millipore) and a 0.1 urn polyvinylidene fluoride membrane filter (Durapore®, Millipore) connected in tandem. Confirm the integrity of each filter before and after the filtration. Take approximately 100 mL of the filtrate in order to check bioburden.

Filter the prefiltered compounded solution through a sterile filter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter and a 0.1 urn polyvinylidene fluoride membrane filter connected in tandem, and introduce the final filtrate into an aseptic room. Confirm the integrity of each filter before and after the filtration.

Processing of Vial, Stopper and Flip-Off Cap

Wash a sufficient quantity of 28 mL vials with water for injection and sterilize the washed vials by a dry-heat sterilizer. Then transfer the sterilized vials into a Grade A area located in an aseptic room.

Wash a sufficient quantity of stoppers with, water for injection. Sterilize and dry the washed stoppers by steam sterilizer. Then transfer the sterilized stoppers into a Grade A area located in an aseptic room.

Sterilize a sufficient quantity of flip-off caps by steam sterilizer. Then transfer the sterilized flip-off caps into a Grade A or B area located in an aseptic room.

Filling and Partially Stoppering

Adjust the fill weight of the filtered compounded solution to 11.37 g (corresponds to 10 mL of the compounded solution), then start filling operation. Check the filled weight in sufficient frequency and confirm it is in target range (11.37 g±1%, 11.26 to 11.43 g). When deviation from the control range (11.37 g±2%, 11.14 to 11.59 g) is occurred, re-adjust the filling weight.

Immediately after a vial is filled, partially stopper the vial with a sterilized stopper. Load the filled and partially stoppered vials onto the shelves of a lyophilizer aseptically.

Lyophilization to Crimping, Visual Inspection, Labeling and Packaging

After all filled and partially stoppered vials are loaded into a lyophilizer, start the lyophilization program shown in FIG. 4. Freeze the loaded vials at −40° C. and keep until all vials freeze. Forward the program to primary drying step (shelf temperature; −20° C., chamber pressure; 100 to 150 mTorr). Primary drying time should be determined by monitoring the product temperature. Forward the program to secondary drying step (shelf temperature; 30° C., chamber pressure; not more than 10 mTorr) after completion of the primary drying step. After all vials are dried completely, return the chamber pressure to atmospheric pressure with sterilized nitrogen. Then stopper vials completely.

Unload the lyophilized vials from the chamber and crimp with sterilized flip-off caps.

Subject all crimped vials to visual inspection and label and package all passed vials.

Example 4 Manufacturing Procedure of Ceftolozane Mono Product 1.1. Preparation of the Compound Solution of CXA-101 Lyophilized Product

1) Weigh 30 kg of water for injection into the compounding vessel;

2) Add 100 g of citric acid, anhydrous and 150 g of sodium bicarbonate into the compounding vessel and dissolve them with mixing;

3) Weigh 5,000 g potency of CXA-101 drug substance and suspend it with mixing. (Note any generation of carbon dioxide.) 4) Slowly add 1,100 g of sodium bicarbonate and dissolve CXA-101 with mixing. (Again, note any generation of carbon dioxide.)

5) Add 1,146 g of sodium chloride and 10,000 g of maltose, dissolve with mixing.

6) Purge dissolved carbon dioxide in the solution with nitrogen until the pH of the solution does not change.

7) Adjust the pH of the solution to 6.0±0.1 with 5%-sodium bicarbonate solution.

8) Adjust the total weight to 56,850 g (D₂₀=1.137) with water for injection.

9) Confirm the pH of the compounded solution within the range 6.0±0.1.

1.2. Prefiltration and Sterile-Filtration

10) Filtrate the compounded solution with a sterile tilter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter (Durapore®, Millipore) and a 0.1 urn polyvinylidene fluoride membrane filter (Durapore®, Millipore) connected in tandem. Confirm the integrity of each filter before and after the filtration. Take approximately 100 mL of the filtrate in order to check bioburden.

11) Filter the prefiltered compounded solution through a sterile filter-set which consists of a 0.2 um polyvinylidene fluoride membrane filter and a 0.1 urn polyvinylidene fluoride membrane filter connected in tandem, and introduce the final filtrate into an aseptic room. Confirm the integrity of each filter before and after the filtration.

1.3. Processing of Vial, Stopper and Flip-off Cap

12) Wash a sufficient quantity of 28 mL vials with water for injection and sterilize the washed vials by a dry-heat sterilizer. Then transfer the sterilized vials into a Grade A area located in an aseptic room.

13) Wash a sufficient quantity of stoppers with, water for injection. Sterilize and dry the washed stoppers by steam sterilizer. Then transfer the sterilized stoppers into a Grade A area located in an aseptic room.

14) Sterilize a sufficient quantity of flip-off caps by steam sterilizer. Then transfer the sterilized flip-off caps into a Grade A or B area located in an aseptic room.

1.4. Filling and Partially Stoppering

15) Adjust the fill weight of the filtered compounded solution to 11.37 g (corresponds to 10 mL of the compounded solution), then start filling operation. Check the filled weight in sufficient frequency and confirm it is in target range (11.37 g±1%, 11.26 to 11.43 g). When deviation from the control range (11.37 g±2%, 11.14 to 11.59 g) is occurred, re-adjust the filling weight.

16) Immediately after a vial is filled, partially stopper the vial with a sterilized stopper. Load the filled and partially stoppered vials onto the shelves of a lyophilizer aseptically.

1.5. Lyophilization to Crimping, Visual Inspection, Labeling and Packaging

17) After all filled and partially stoppered vials are loaded into a lyophilizer, start the lyophilization program shown in FIG. 4. Freeze the loaded vials at −40° C. and keep until all vials freeze. Forward the program to primary drying step (shelf temperature; −20° C., chamber pressure; 100 to 150 mTorr). Primary drying time should be determined by monitoring the product temperature. Forward the program to secondary drying step (shelf temperature; 30° C., chamber pressure; not more than 10 mTorr) after completion of the primary drying step. After all vials are dried completely, return the chamber pressure to atmospheric pressure with sterilized nitrogen. Then stopper vials completely.

Example 5 Analytical HPLC Method A. Operative Conditions

Column Develosil ODS-UG-5; 5 μm, 250 × 4.6 mm (Nomura Chemical, Japan) Mobile phase Sodium Perchlorate Buffer Solution (PH 2.5)/CH₃CN 90:10 (vlv) Flow rate 1.0 mL/min Wavelength 254 nm Injection volume 10 μL Oven Temperature 45° C. Run Time 85 minutes

Gradient Profile:

Time (min) A % B % 0 75 25 30 70 30 60 0 100 85 0 100 85.1 75 25 110 75 25

B. Mobile Phase Preparation.

Sodium Perchlorate Buffer Solution was made by dissolving 14.05 g of sodium perchlorate Monohydrate in 1000.0 mL of water followed by adjusting pH to 2.5 with diluted perchloric acid (1 in 20).

Mobile Phase was then made by mixing Sodium Perchlorate Buffer Solution (pH 2.5) and acetonitrile in the ratio 90:10 (v/v).

Sodium Acetate Buffer Solution pH 5.5 (Diluent) was made by dissolving 1.36 g of sodium acetate trihydrate in 1000.0 mL of water followed by adjusting to pH 5.5 with diluted acetic acid (1 in 10).

C. Sample Preparation.

Sample solution: dissolve 20.0 mg, exactly weighed, of Sample, in 20.0 mL of water (Prepare just before injection into HPLC system).

System Suitability Solution (1%): take 1.0 mL of the Sample Solution (use first sample if more are present) and transfer into a 100.0 mL volumetric flask, dilute with water to volume and mix.

D. HPLC Analysis Procedure

1. Inject Blank (water) 2. Inject System Suitability Solution and check for tailing factor and theoretical plate number for CXA-101 peak:

-   -   The tailing factor must not be greater than 1.5     -   Theoretical plates number must not be less than 10000

3. Inject Sample Solution

4. Inject System Suitability Solution and check for tailing factor and theoretical plate number for CXA-101 peak.

-   -   The tailing factor must not be greater than 1.5     -   Theoretical plates number must not be less than 10000         5. Identify the peaks of Related Substances in the Sample         chromatogram based on the reference chromatogram reported in         FIGS. 1A and 1B or, alternatively, on the basis of the RRT         values reported in Table 1 (FIG. 2).

E. Calculations

I. Report for each related substance its amount as expressed by area percent.

$C_{i} = \frac{A_{i} \times 100}{A_{t} + {\Sigma \; A_{i}}}$

wherein:

C_(i)=Amount of related substance i in the Sample, area %

A_(i)=Peak area of related substance i in the Sample chromatogram

A_(t)=Area of CXA-101 peak in the Sample chromatogram

A_(t)+τA_(i)=Total peaks area in the Sample chromatogram

Consider as any Unspecified Impurity, each peak in the chromatogram except CXA-101, peaks from 1 to 11 and every peak present in the blank chromatogram and report the largest.

II. Report the total impurities content as expressed by the following formula:

$C_{T} = \frac{A_{i} \times 100}{A_{t} + {\Sigma \; A_{i}}}$

wherein:

C_(T)=total impurities content in the Sample, area %

A_(t)=area of CXA-101 peak in the sample chromatogram

ΣA_(i)=total peak areas of impurities in the sample chromatogram 

1. A pharmaceutical composition comprising stabilized ceftolozane obtained by a process comprising lyophilizing a composition including ceftolozane and a stabilizing agent selected from the group consisting of: sodium chloride, sucrose, and trehalose, to obtain a lyophilized stabilized ceftolozane pharmaceutical composition, wherein the stabilized ceftolozane is characterized by a reduction in purity of less than 5% at 60 degrees C. over 7 days in a sealed container, as determined by a Develosil column ODS-UG-5; 5 micrometers; 250×4.6 mm, a mobile phase of sodium perchlorate buffer solution (pH 2.5)/CH₃CN 90:10 (v/v) at a 1.0 mL/min flow rate and oven temperature of 45° C.
 2. The pharmaceutical composition of claim 1, wherein the lyophilized stabilized ceftolozane pharmaceutical composition after 3 days at 70 degrees C. after lyophilization comprises at least about 70% of an initial amount of ceftolozane after lyophilization.
 3. The pharmaceutical composition of claim 1, wherein the lyophilized stabilized ceftolozane pharmaceutical composition contains 1,000 mg of ceftolozane active.
 4. The pharmaceutical composition of claim 1, wherein the stabilizing agent is selected from the group consisting of sucrose and trehalose.
 5. The pharmaceutical composition of claim 4, wherein the stabilized ceftolozane is obtained by a process comprising lyophilizing a solution comprising ceftolozane, L-arginine and the stabilizing agent.
 6. The pharmaceutical composition of claim 4, wherein the stabilized ceftolozane comprises is obtained by a process comprising lyophilizing a composition comprising about 1,000 mg of ceftolozane.
 7. The pharmaceutical composition of claim 4, wherein the stabilized ceftolozane is obtained by a process comprising lyophilizing a composition comprising about 300-500 mg of the stabilizing agent.
 8. The pharmaceutical composition of claim 1, wherein the stabilizing agent comprises sucrose and trehalose.
 9. The pharmaceutical composition of claim 1, wherein the stabilized ceftolozane is obtained by a process comprising lyophilizing a solution comprising ceftolozane, citric acid, L-arginine and about 100-500 mg of the stabilizing agent.
 10. A pharmaceutical composition comprising stabilized ceftolozane and about 300 mg of a stabilizing agent, wherein the stabilizing agent is selected from the group consisting of sucrose and trehalose.
 11. The pharmaceutical composition of claim 10, wherein the stabilizing agent comprises trehalose and sucrose.
 12. The pharmaceutical composition of claim 10, wherein the stabilizing agent further comprises sodium chloride.
 13. The pharmaceutical composition of claim 10, further comprising L-arginine and citric acid.
 14. The pharmaceutical composition of claim 10, wherein the pharmaceutical composition comprises 1,000 mg ceftolozane active per unit dose.
 15. The pharmaceutical composition of claim 10, wherein the pharmaceutical composition comprises about 300 mg of the stabilizing agent per 1,000 mg of the ceftolozane active.
 16. The pharmaceutical composition of claim 15, wherein a. the stabilizing agent further comprises sodium chloride; b. the pharmaceutical composition comprises 1,000 mg ceftolozane active per unit dose; and c. the pharmaceutical composition further comprises about 500-700 mg L-arginine per 1,000 mg of ceftolozane active.
 17. A unit dosage form container enclosing a pharmaceutical composition formulated for parenteral administration for the treatment of complicated intra-abdominal infections or complicated urinary tract infections, the pharmaceutical composition comprising 1,000 mg of ceftolozane active, L-arginine, citric acid and about 300-500 mg of a stabilizing agent selected from the group consisting of: sodium chloride, trehalose, and sucrose, wherein the pharmaceutical composition after 7 days at 60 degrees C. wherein the reduction in the purity of ceftolozane active in the pharmaceutical composition is not more than 5% less than the initial amount.
 18. The container of claim 17 containing 300 mg of a stabilizing agent selected from the group consisting of trehalose and sucrose.
 19. The container of claim 17, wherein the pharmaceutical composition is obtained by lyophilizing an aqueous solution comprising about 300-500 mg of the stabilizing agent, an amount of ceftolozane sulfate containing 1,000 mg of ceftolozane active, citric acid, and L-arginine to obtain the pharmaceutical composition as a lyophilized composition.
 20. The container of claim 19, further comprising tazobactam sodium. 